The present invention generally relates to a flexible cable assembly which transmits torque between rotary shafts and, more particularly, to such a flexible cable assembly for powered adjustable seats, adjustable pedals or the like used in motor vehicles.
Flexible cables are used in many applications to transmit rotary motion or torque from a driving shaft to a driven shaft. The flexible cable typically includes an outer protective sheath or casing and an inner drive member or core disposed within the outer protective casing. The ends of the outer protective casing are attached to fixed members such as motor or gear box housings and the ends of the core are connected to driving and driven elements such as rotary shafts. The driving element moves the core which transfers the movement to the driven element. Flexible cables are advantageous because they transfer movement when there is misalignment or noncoaxial alignment between the driving and driven elements. The flexible cables, however, often have vibration during operation which can cause undesirable noise and can become unintentionally disconnected due to vibrations or other forces.
Attempts have been made to strengthen the connection of flexible cables. See, for example, U.S. Pat. No. 5,397,270, the disclosure of which is expressly incorporated herein in its entirety by reference, which discloses a flex shaft cover retention device. The cover or sheath of the flex shaft is stretched over a fixed coupling having at least one radially extending projection. While this retention device may be an improvement over some prior art configurations, it remains less than ideal. The pull off strength of the sheath may be less than desirable because of the lack of an interlocking connection between the sheath and the coupling. Additionally, the sheath is difficult to install due to the amount of stretching that is required and may not be reusable do to stretching. Accordingly, there is a need in the art for an improved flexible cable assembly which has ease of assembly, adequate pull off strength, and/or reduced noise caused by vibrations during operation.
The present invention provides a flexible drive cable assembly which overcomes at least some of the above-noted problems of the related art. According to the present invention a flexible drive cable assembly comprises, in combination, an elongate flexible core for transmitting movement from a first end of the core to a second end of the core and an elongate flexible casing encircling a longitudinal length of the core and having a unitary connector. An element is operably connected to the core for transmission of movement therebetween. An end fitting is stationary relative to the element and has an aperture for passage of the core therethrough. The unitary connector of the casing cooperates with the end fitting to secure the casing to the end fitting and hold the casing stationary relative to the end fitting.
According to another aspect of the present invention, a flexible drive cable assembly comprises, in combination, an elongate flexible core for transmitting movement from a first end of the core to a second end of the core and an elongate flexible casing encircling a longitudinal length of the core and having a connector. An element is operably connected to the core for transmission of movement therebetween. An end fitting is stationary relative to the element and has an aperture for passage of the core therethrough. The connector of the casing and the end fitting form a snap-fit connection to secure the casing to the end fitting and hold the casing stationary relative to the end fitting. Additionally, the casing forms an interference fit with the end fitting to reduce vibration therebetween.
According to yet another aspect of the present invention, a flexible drive cable assembly comprises, in combination, an elongate flexible core for transmitting movement from a first end of the core to a second end of the core and an elongate flexible casing encircling a longitudinal length of the core and having generally coaxial inner and outer surfaces. An element is operably connected to the core for transmission of movement therebetween. An end fitting is stationary relative to the element and has an elongated portion with an outer surface and an aperture for passage of the core therethrough. The outer surface of the elongated portion has at least one groove formed therein. The casing extends over the elongated portion with the inner surface of the casing engaging the outer surface of the elongated portion. The casing has at least one protrusion extending from the inner surface of the casing and into the groove of the elongated portion to interlock the casing with the end fitting and to hold the casing stationary relative to the end fitting.
According to even yet another aspect of the present invention, a flexible drive cable assembly comprises, in combination, an elongate flexible core for transmitting movement from a first end of the core to a second end of the core and an elongate flexible casing encircling a longitudinal length of the core and having a connector. The connector of the casing comprises an elongated portion having a generally cylindrically shaped outer surface and a flange extending generally perpendicular to the outer surface of the elongated portion. An element is operably connected to the core for transmission of movement therebetween. An end fitting is stationary relative to the element and has an aperture for passage of the core therethrough. The elongated portion of the connector extends through the aperture of the end fitting and the flange of the connector engages the end fitting adjacent the aperture of the end fitting to secure the casing to the end fitting and to hold the casing stationary relative to the end fitting. In a preferred embodiment, the outer surface of the casing connector forms a press fit with the aperture of the end fitting.
From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of flexible drive cable assemblies. Particularly significant in this regard is the potential the invention affords for providing a high quality, reliable, light weight, low cost assembly which is relatively quiet during operation. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.